Monday, May 3, 2010

A consistent message is being spread by the wastewater industry about greywater which I have been perplexed by, but think I am starting to understand why. Take, for example, this article from The Daily Lobo (The Independent Voice of University of New Mexico since 1895) where they quoteKatherine Yuhas who is the water conservation officer at the Albuquerque Water Authority:

“The state regulates gray water. And, in 2003, the state made it legal to use up to 250 gallons of gray water per day,” Yuhas said. “It’s not very popular at all, frankly. We don’t promote the gray water program. We don’t offer rebates for it. The reason is that we treat water at our water reclamation plant to a much higher standard than you could in your yard.”

I did not realize that someone's yard was in competition for water "treatment" with a wastewater treatment plant. Ms. Yuhas is silent whether or not the treated water is available for the homeowner to reuse in their yard, which I think is the idea behind greywater reuse.

But I think the issues are becoming clearer to me after reading the AWWA White Paper on Graywater, where it states:

"There have not been any documented cases of human health problems due to water reuse under standards, criteria, and regulations. The water reuse industry is unwavering in its intent to maintain this record with diligent operation of water recycling systems and has worked hard to educate the public about its safety record. It is, therefore, not surprising that the industry is constantly on guard to prevent a reversal of its increasingly positive public image....The recycled water industry takes immense pride in contributing significantly to our scarce water resources. Therefore, anything that might diminish the source of this water supply would be of great concern to the industry".

It is clear that the wastewater industry is out to "win our hearts and minds" with their apparent public information campaign of protecting the public. Greywater reuse is perceived as a threat to their "positive public image" by the wastewater industry.

But the confusion about their message starts to cloud when one reads further in the AWWA White Paper on Graywater, where "A large proportion of graywater systems are deployed in rural areas and in residences that are not connected to a central sewerage system and/or are not served with a piped water system. Thus, the diversion of graywater from their onsite treatment/disposal system would have no effect on a central water reclamation system".

If this statement is indeed true, then why is the wastewater industry so against greywater reuse if it is truly a "rural" phenomena? Let's explore the issue further through the lens of dollars and "sense".

This presentation and this AWWA publication determined that the average rates charged for reclaimed water range from 70 to 90% of potable water rates. Reclaimed water is not only colored purple, but also with flecks of goldwater. The more purplewater that is available for "resale", the larger the "profits".

According to the AWWA, "There are no peer-reviewed survey research results available regarding actual volumes of graywater diverted and used". Projected graywater reuse in 2030 is estimated at 10% of homes in the US by the AWWA. The Rainbow Water Coalition used current numbers of homes and estimated cost savings quoted from an AWWA study in Canada to come up with "lost" revenues to the Oregon wastewater industry approaching $10 to 14 million per year.

Digging a little deeper into the AWWA white paper reveals the following statistic: "Assuming an average of 75.5 gpd per household, the maximum total daily diversion of graywater would amount to 128 mgd in California and 604 mgd in the United States". Recalling the other AWWA study in Guelph, Ontario that was recently mentioned in the Rainbow Water Coalition "Each reuse system is expected to reduce the water used by a family of two by approximately 32,850 L (8,678 gallons) per year and to reduce water and wastewater utility costs by approximately Can$73 (US$73) annually per household"....

Let's assume greywater reuse can be undertaken for about six months per year in the US. If one divides "annual" daily diversion of greywater in the US by the number of gallons saved per home cited above to get the number of homes, then if one multiplies this value by the annual "savings" to the average homeowner it yields over $900 Million per year in "lost" revenues to the wastewater industry. Even if one assumes that greywater is only diverted for only three months per year (one half of the time assumed in the calculations), this is still some serious money. But if these savings are only realized by "rural" residences, then what is the wastewater industry worried about?

It comes as no surprise that the wastewater industry is not fond of greywater reuse. It not only cuts out sales of reclaimed water, but it also cuts into the operating revenues of the wastewater industry by nearly $1 Billion. I think I am starting to see what really is being "protected".

And let's not forget that we heard a few words about the lack of fondness for greywater reuse from Pat Mulroy when she dissed greywater in favor of purplewater so that the Southern Nevada Water Authority could continue its power struggle over "new" water from the Colorado River (where Las Vegas reclaimed wastewater goes so they get "credit" for their diversions from Lake Mead) or from their proposed Snake Valley pipeline. Keeping the greywater reuse in Las Vegas to a minimum helps maintain the hydro-hegemony of the Colorado River and the Great Basin Carbonate Aquifer.

No week would be complete without the Greywater Gadget of the Week which is the Aqua2use Greywater System. This unit uses a unique filtration system to remove impurities in greywater. According to greywater reuse convert Jenni Sabiani "it's such a great and easy system". If you have any questions, feel free to contact Jenni (jenni at waterwisegroup.com). Thanks for following the Rainbow Water Coalition, Jenni!

6 comments:

Nice post, I think I'll share it. In my neighborhood, the local utility doesn't or won't give a nod to greywater reuse because they have to maintain the existing designed level of water service in order to maintain fire flow pressures in the system. Are there any water supply systems that don't also provide fire flows?

I don't know anything about the potential of diminishing fire flows due to greywater reuse at a residential scale. I guess I can't envision the connection to greywater reuse unless the fire flows are maintained in a system of piping for "reclaimed" water that is separate from the drinking water supply. Then the reused greywater would more than likely diminish the quantity of water for fire flows. But I think many municipal systems using their drinking water supplies as part of the fire suppression system, too. Thanks for the comment, though. A good question hopefully a civil engineer practicing in the municipal field can help us out with answering.

Found your blog... I enjoyed the descriptions of the various "colors" of water, and will read more later. Here's mine: an eclectic mix of shiny things that catch my attention, but particularly geoscience, humor and politics. I've also been taking primary responsibility for The Accretionary Wedge, the geoblogospheric carnival.

Todd - I think you have mostly nailed it on the head. Although I don't really think "profit" per se is so much the motive because most large municipal wastewater systems are public entities that aren't really allowed to make profits. They do however get to increase their budgets by expanding and upgrading their systems - which expanded graywater utilization would definitely cut into.I have also heard one concern from our local wastewater entity in Tucson that increased diversion of graywater to non-potable uses in the home would effect the ability of the sewer system to adequately convey waste because of decreased liquid volume. Seems most systems are engineered to handle a consistent proportion of liquids and solids with slopes designed to move things along effectively. They haven't been actively discouraging use of graywater but have admitted that they occasionally flush sewer lines with (potable) water to prevent plugging. Aaargh!

Thanks for your comment. You are correct *profit* comes in many forms. I am thinking *profit* includes *protecting a paycheck* or *protecting the consulting and construction industry bottom line*, among other things.

I asked a wastewater engineer working for one of the big design/build firms about the reduced flows and effects on the plant operation. They indicated that the plants can handle the reduced flows - they are not designed to be so *fine tuned*. The sewer system question is an interesting one, but it seems like the US wastewater generation is more in line with the rest of the world rate and volume of wastewater generation WITH greywater reuse, but that one does not hear of problems with their sewers. The *plugging* problem and use of potable water for flushing sounds more like a *paper* problem rather than a *solids* problem! The solution appears to mimic how to generate *clean* greywater - educate at the upstream side (in the home) rather than trying to treat the downstream side.

We missed you on Watering the Desert. Welcome back. Thanks for reading!

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About Me

This blog was an experiment in social media and networking for a class that I teach in water science and policy. You will find more than 300 postings here searchable through the key word search bar. Want to learn more about cool greywater equipment, type "gadgets"; "living building", etc. Type in "permit" to learn more about permitting greywater systems. Opinions are my own even though the blog is used as a learning resource. Thanks for reading.

Colors of the blog logo?

The Peace Flag? The Gay Pride Flag? All good guesses, but no, it is the Cuzco Wiphala which I first observed in 1984 in Cuzco at the Inti Raymi festival. It consists of seven horizontal stripes representing the colors of the rainbow. The significance and meanings for each color are as follows:

Red: The Earth and people

Orange: Society and culture

Yellow: Energy

Green: Natural resources

Light Blue or White: Time

Blue: The heavens

Purple: Self-determination

Colors of Water

Clearwater many times thought to have come from a fresh water spring. Because water is composed of hydrogen and oxygen and both elements are invisible gases is a reason why water has crystal clear appearance.Tough to find these days in a natural state. Easy to find in a manufactured state and trapped in a bottle.

Whitewater, historical reference to noncorrupt activities by the Clintons pursued by a former special prosecutor. Sometimes also refers to water with lots of air or dissolved gas.Also connected to rapidly flowing water in rivers where lots of fun can be had in a multitude of floating devices. With incompetence in one arena, and competent treatment in the others, these waters remain harmless.

Greywater or graywater has many different definitions, I guess some could say “quasi conspiratorial” if one considers that graywater is neutral between whitewater and blackwater, but my previous job as a volunteer for the State of Oregon focused on HB 2080 which defines graywater as: “shower and bath waste water, bathroom sink waste water, kitchen sink waste water and laundry waste water. Graywater does not mean toilet or garbage wastes or waste water contaminated with soiled diapers.”No grey area in this definition.

Blackwater has many forms including a name formerly connected to a defense contractor who apparently liked the color of water in the Great Dismal Swamp of North Carolina. Also a Doobie Brothers. But in the water world, it is untreated wastewater from both urban domestic use and rural septic tanks. Blackwater also occurs in Australia as organic material, such as leaves and bark, that is washed into the river by a flood thus causing oxygen depletion. It can also be derived from dissolved manganese in groundwater and commonly stains porcelain fixtures.Peaceful means of treatment ultimately prevail against this colored water, but use extreme caution, some variants can be deadly.

Brownwater or the tea-colored water famous in swampy areas along the Mississippi River and Amazon River where rotting vegetation and humic and fulvic acids abound.

Greenwater is precipitation water infiltrated into the soil (so-called ‘‘green water’’) made famous by the grand dame of water mavens Malin Falkinmark of the Stockholm International Water Institute. Also greywater that has been disinfected for later use for irrigation becomes green.

Bluewater is water withdrawn and water consumed (withdrawal minus return flow to the river system) from rivers, lakes and aquifers for the purpose of irrigation.Also found as the water in nuclear power plants where spent rods are stored, but the subject of a different blog (wherever that might be).

Redwater is common when the water purveyor is tinkering with piping network, especially old piping networks, where sediment and rust are stirred up during servicing.Can also be a function of iron bacteria in water.

Purplewater is sometimes thought derived from Purple Rain popularized by the performer once known as Prince, but now referred to as recycled water from wastewater treatment plants conveyed in purple colored pipes for non-potable uses.

Yellowwater is a variant of yellow snow, derived from “where the huskies go" (homage to Frank Zappa).